There are a number of different circumstances in the manufacture or handling of business forms when it is desirable to have a high capacity conveyance or stacking of forms. For example, the Moore 4800 Pressure Seal System, available from Moore Business Forms of Lake Forest, Ill., pressure seal mailer type business forms are produced and then delivered to an outfeed conveyor. It is desirable to have an outfeed which is large enough to accommodate a substantial number of forms (e.g. typically at least twenty inches and preferably about a two foot stack of forms, depending upon size, weight, fold type, and insert presence), and which can be unloaded while the machine is running.
A number of different stackers have been utilized in association with such systems, such as shown in U.S. Pat. No. 5,409,207 (the disclosure of which is incorporated by reference herein). Other stackers that have been utilized include a power drop-stacker that is similar to the Moore 7400 stacker in which forms are piled on a shelf until they reach a sensor that activates and lowers the shelf. A third type of stacker that has been utilized in such systems is a spring loaded stacker which utilizes a platform mounted on two rods in such a way that the unit swings down while the platform remains horizontal. However, all of these stackers have a number of disadvantages associated therewith for some circumstances, and also it may be difficult to integrate them with a simple yet effective job separator, such as a job separator disposed between the pressure sealer or other business forms manufacturing or handling equipment, and the outfeed conveyor.
According to the present invention a system, delivery mechanism, and method are provided which allow the build up of at least twenty inches of forms in a simple and reliable manner, can be unloaded as the machine is running, and may be easily integrated with an effective job separator upstream thereof.
According to one aspect of the present invention a high capacity conveyor assembly for business forms is provided. Any business form can be handled thereby, such as mailer type business forms with or without inserts, single sheet forms, forms that are unfolded or that are folded (e.g. V, Z or C folded), or in some circumstances even plain paper sheets. The assembly comprises the following elements: An infeed conveyor having a first conveyance surface and for feeding forms in a first direction. An outfeed conveyor having a second conveyance surface and for feeding forms in the first direction. A pair of nip wheels between the infeed and outfeed conveyors for receiving a business form from the infeed conveyor and directing the business form to the outfeed conveyor in the first direction, the pair of nip wheels including a top nip wheel and a bottom nip wheel with a nip between them, the bottom nip wheel having a top peripheral surface closer to the outfeed conveyor than is the nip. And a transition element between the nip and the outfeed conveyor, the transition element including a form-supporting surface lower than the bottom nip wheel top peripheral surface.
The transition element may comprise a shelf, with the form supporting surface comprising a top surface of the shelf, and of low friction material. For example, the shelf (including the top surface) may be of stainless steel, or the top surface may be of polytetrafluoroethylene or have a polytetrafluoroethylene coating. Also, a first sensor is typically provided for sensing building up forms on the transition element. A first motor powers the outfeed conveyor, and a controller controls operation of the first motor to convey forms away from the transition element when the first sensor senses a build up of forms thereon.
The first conveyance surface is typically located on a lower level than the second conveyance surface and both the first and second conveyance surfaces are substantially horizontal. A slanted guide surface on which business forms travel and are guided from the first conveyance surface to the nip, is preferably also provided. The nip wheels are preferably powered by a second motor, controlled by the controller independently of the first motor, and the upper nip wheel is spring pressed into engagement with the lower nip wheel at the nip.
The outfeed conveyor may be of a wide variety of types. For example, it may under some circumstances be a table with a pusher mechanism associated with it, or a movable backstop, or it may include rollers, wheels, ball bearings, or like conveyance elements as the second conveyance surface. Alternatively, a wide variety of powered mechanisms can be utilized such as powered rollers, wheels, ball bearings, or the like, powered rigid elements, or a wide variety of other conventional constructions. In the preferred embodiment, however, the outfeed conveyor comprises first and second rolls over which a plurality of endless conveyor belts or tapes pass, a top surface of the endless belts or tapes defining the second conveyance surface. The second conveyance surface has a first end adjacent the transition element and a second end remote from the transition element, and the second conveyance surface is at least about twenty inches long (typically at least about two feet long); that is, the substantially horizontal spacing between the first and second ends of the second conveyance surface is at least about twenty inches. A second forms-sensing sensor may be adjacent a second end of the second conveyance surface for providing input to the controller. The sensors may be of any suitable type, such as magnetic, capacitive, electromagnetic, tactile, or almost any other conventional sensor construction. Preferably, however, the sensors are optical sensors, either of the reflective type, or with an emitter on one side of the conveyor and a detector on the opposite side (i.e. a through-beam optical sensor).
The infeed conveyor can also be of a wide variety of types, such as described above with respect to the outfeed conveyor. Preferably, however, the infeed conveyor comprises a job separator conveyor powered by a third motor. Various job separator constructions that may be utilized according to the invention are shown in U.S. Pat. Nos. 5,238,164 and 5,265,731 (the disclosures of which are hereby incorporated by reference herein).
In the preferred form, the job separator and feed conveyor according to the invention may comprise powered conveyor elements powered by a third motor and mounted on a carriage having a first, infeed, end remote from the nip wheels and a second, outfeed end adjacent the nip wheels and pivotally mounted (for movement about a vertical pivot axis) near the first end thereof, and substantially linearly movable adjacent the second end thereof to pivot about the vertical pivot axis thereof. The nip wheels are particularly desirable for use in association with such a structure because the nip wheels positively grasp the forms when being conveyed in a first direction, and once they grab the forms even if the job separator conveyor starts shifting (to initiate a job separation action) the form grasped by the nip wheels will not in any way be adversely affected, ensuring proper separation, preventing re-merging of forms, and also allowing high capacity outfeed where there is plenty of space for the separated forms to lay so that they do not get mixed up as the conveyor moves.
A particular conveyor system according to the present invention, utilizing a novel infeed conveyor, also is provided comprising the following elements: A job separator infeed conveyor, powered by a first motor, and having a first conveyance surface and for feeding forms in a first direction. An outfeed conveyor having a second conveyance surface and for feeding forms in the first direction. A transition between the infeed and outfeed conveyors for transferring forms from the infeed conveyor to the outfeed conveyor wherein the first conveyance surface and the first direction are substantially horizontal. And wherein the job separator infeed conveyor comprises: at least one powered conveyor element, powered by the first motor, mounted on a carriage, and having a first, infeed, end, and a second, outfeed, end; means for pivotally mounting the carriage closer to the first end thereof than the second end thereof for pivotal movement about a first substantially vertical axis; and means for substantially linearly moving the carriage adjacent the second end thereof in a second substantially horizontal direction, substantially perpendicular to the first direction, so that the carriage pivots about the first substantially vertical axis.
The means for substantially linearly moving the carriage adjacent the second end thereof may comprise a wide variety of structures, such as one or more solenoids, one or more pneumatic or hydraulic piston/cylinder assemblies, one or more rotating screws with traveling nut structures, or a wide variety of other conventional substantially linear actuators (connected so as to accommodate the pivotal movement that ensues from the substantially linear action thereof). In the preferred form according to the invention, however, the means for substantially linearly moving the carriage adjacent the second end thereof comprises: a stepper motor having a shaft and an arm extending substantially perpendicular to the shaft; a slotted portion of the carriage adjacent the second end having an elongated slot therein; and a connector between the arm and the slot, so that rotation of the shaft is translated into substantially linear movement of the carriage slotted portion in the second direction.
The means for pivotally mounting the carriage may also comprise a wide variety of different structures, almost any conventional type of pivotal arrangement, whether located above, below, or at the sides of, the carriage being suitable. However, one particularly desirable pivotally mounting means comprises a substantially vertical shaft extending into engagement with the carriage from a position below the carriage, and suitable bearing means cooperating between the shaft and the carriage, the bearing means being of a wide variety of different types including thrust, roller, needle, or low friction stationary surface, bearings.
According to another aspect of the present invention a method of delivering forms each having a leading and a trailing edge, using a pair of powered nip wheels including an upper nip wheel and a lower nip wheel with a nip between them and positioned so that the lower nip wheel has an upper peripheral surface that is vertically above the nip, and horizontally spaced from the nip in a first direction, is provided. The method comprises the steps of: (a) Moving a business form in a first direction toward the nip wheels. (b) Grasping the business form with the nip wheels and continuing to move the form in the first direction until the trailing edge of the form moves through the nip. (c) Engaging the trailing edge of the form with the upper peripheral surface of the lower nip wheel after the form moves through the nip so that the form trailing edge continues to move in the first direction, and then downwardly, after passing through the nip, to a transition position. And (d) moving the form away from the transition position in the first direction.
Step (d) may be practiced at spaced time intervals, and in response to sensing (e.g. with an optical sensor) of the build up of forms at the transition position. A low friction surface may be provided at the transition position in which forms may be built up, and step (c) may then be practiced to move forms in sequence along the low friction surface until build up thereof is sensed. Step (b) may be practiced so as to move each form in the first direction at a slightly greater speed than the form is moved in the first direction during the practice of step (a) (or at the same speed). The business forms may be of any suitable type, but in one preferred example according to the invention are pressure sealed business forms, sealed in a pressure sealer, and step (a) may then be practiced to move forms in sequence, away from the pressure sealer.
The invention also relates to a business forms delivery mechanism per se. The delivery mechanism comprises the following elements: A pair of nip wheels for receiving a business form and directing the business form in a first direction, the pair of nip wheels including a top nip wheel and a bottom nip wheel with a nip between them, the bottom nip wheel having a top peripheral surface above the nip and downstream of the nip in the first direction; and a shelf downstream of the nip in the first direction, and including a form-supporting top surface, the shelf top surface lower than the bottom nip wheel top peripheral surface. The forms supporting surface may be of low friction material, e.g. of stainless steel (the whole shelf may be of stainless steel), or of--or coated with--Teflon.RTM..
It is a primary object of the present invention to provide for the effective and versatile delivery and stacking of business forms, including with high capacity outfeed and/or job separation capabilities. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.